Throughout our years of tunneling, Bradshaw Construction Corporation has worked on many complicated, sophisticated, and cutting edge projects.
Each of those projects led us to find innovative solutions to unique problems. We invite you to take an in-depth look at projects where you will see the problems we encountered and how we solved them.
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SUMMARY: The Cow Branch Sewer project in Woodbridge, VA, consisted of the installation of approximately 8,000' of new gravity sewer main in the 8" to 36" diameter size range. 944' of 36" sewer main was to be installed via microtunneling under a wetland area that empties into the Potomac River. This project represented the Prince William County Authority's (PWCSA) first microtunneling project. In lieu of... Complete Project Profile

SUMMARY: Bradshaw Construction microtunneled a single 370 linear feet drive of 30 inch steel casing under I-664 in Suffolk, VA. The subsurface conditions consisted of loose clayey & silty sands (SC & SM) below the groundwater table. Settlement was less than an 1/8 of an inch. Bradshaw installed a 16 inch restrained joint ductile iron pipe for a water main inside the jacked casing. Since this was a... Complete Project Profile

SUMMARY: Bradshaw installed 136 linear feet of 50.5 inch steel casing to accommodate a 30 inch ductile iron sewer line under East Brambleton Avenue at the intersection with St. Paul Boulevard in downtown Norfolk,VA. Soil conditions consisted of sand under the water table. Microtunneling was required due to the need to keep the busy intersection open, and because the saturated sand would have been... Complete Project Profile

SUMMARY: Bradshaw Construction contracted with the Fairfax County Department of Public Works to install a new 18" sanitary sewer line across I-66, abandoning a previously installed line. During shaft installation, unforeseen partially weathered schist was encountered that could only be excavated using a hammer drill. Fairfax County performed additional geotechnical investigation to determine the extent... Complete Project Profile

SUMMARY: Bradshaw Construction installed 2,100' of 43" Permalok steel casing for the 18" dedicated fire system. The tunnels were installed by microtunneling through shale beneath active runways, taxiways, and taxi lanes. The microtunneling was completed in four segments, the longest being 585' long under Runway 19L-01R. Bradshaw also installed the 18" DIP in the tunnels once mining was completed. Crews... Complete Project Profile

SUMMARY: Bradshaw Construction has completed three tunnels by microtunneling, totaling 1,183 linear feet, below highways and the Arlington National Cemetery for Arlington County's Potomac Interceptor. 60-inches of steel casing was installed by microtunnel through soft ground to place 42-inch FRP carrier pipe for a gravity sewer on one tunnel. 48-inch RCP was direct jacked through rock and mixed face... Complete Project Profile

SUMMARY: Bradshaw Construction completed two drives with four shafts (two per drive) at each tunnel location for a new waterline. The Medina River drive (726 linear feet) included a 70 and 105 foot deep shafts, respectively. The second tunnel at Medio Creek (543 linear feet) consisted of 50 and 55 foot shafts, respectively. 73.5 inch steel casing was installed by slurry microtunneling for both drives... Complete Project Profile

SUMMARY: Bradshaw was contracted to install twin 36 inch steel casings from a 30 foot deep pump station shaft at the shoreline of Lake Livingston Reservoir to an intake cofferdam in the lake. Each microtunneled casing was 390 foot long and was used to install 24 inch ductile iron carrier pipes. The soil conditions consisted of clay and sandy silt 20 feet below the water table. Due to the non-cohesive... Complete Project Profile

SUMMARY: Bradshaw was selected to install a 43 inch steel casing by microtunnel outside Austin, TX. The microtunnel was launched from a 190 foot deep shaft at the Mansfield Dam on Lake Travis. The 530LF of lined and coated casing was microtunneled into Lake Travis and the MTBM was recovered underwater. Many of the challenges of the project were related to the deep shaft, underwater MTBM recovery and the... Complete Project Profile

SUMMARY: Bradshaw jacked a 59" diameter steel casing 311 feet under interstate highway I-77 behind a microtunnel boring machine (MTBM). The subsurface conditions consisted of clay and sand below the groundwater table. In order to mobilize to the jacking shaft, about a mile of forest was cleared and the equipment was dragged in on sleds. A slide rail system was used for the jacking shaft with special... Complete Project Profile

SUMMARY: The Table Rock Intake project was a technically complex water-intake project, which required pinpoint accuracy. The project involved the installation of a raw water intake tunnel below the Cleveland, SC, dam and its associated reservoir. The project involved a marine retrieval of the MTBM via a miniscule shaft - 8.5' in diameter to be exact. Tunneling under a dam is inherently a highly sensitive... Complete Project Profile

SUMMARY: Bradshaw jacked twin 59" diameter steel casings 320 feet using a microtunnel boring machine (MTBM). The raw water intake alignment went from a new on-shore pump station to a new underwater intake structure in the Susquehanna River. The subsurface conditions consisted of weak to strong schist. The intake structure was under about 20' of water. Several interventions were made into the head of the... Complete Project Profile

SUMMARY: ODEC’s Wildcat Point Generation Facility (WPGF) in Cecil County, MD will use water from the Conowingo Reservoir in Lancaster County, PA. The Wildcat Point Raw Water Supply Project, consisting of a pump house, wet well shaft and pipelines to convey water from the Susquehanna River to WPGF. These pipelines run through an 830', 60" diameter microtunneled Permalok® steel casing, completed in June... Complete Project Profile

SUMMARY: The Delta Power Plant project in Delta, PA, consisted of a 565 MW power generating facility that recovers heat from gas exhaust leaving gas turbines. The turbines burn either natural gas or low sulfur diesel fuel oil. A microtunnel solution to installing the cooling water intake and return was developed by the owner, contractor, and tunnel subcontractor. 1,515' of 60" steel casing was jacked... Complete Project Profile

SUMMARY: To increase capacity and replace an aging sewer pipeline through the Arclermittal Steel facility in Coatesville, PA, Pennsylvania American Water needed to construct a new 30" gravity sewer that would not pass down the plant's main thoroughfare. Bradshaw Construction was contracted to build the trenchless portion this new line parallel to Valley Road. The 1,017' long tunnel was constructed in a... Complete Project Profile

SUMMARY: As part of a major construction project at the Ohio State Medical Center, new chilled water distribution pipelines were designed under the very busy and congested campus. The design included twin pipe-jacked casings under the areas where trenching would have been untenable. Microtunneling was specified. Bradshaw installed 4 microtunnels through glacial deposits below the groundwater table. Complete Project Profile

SUMMARY: Bradshaw installed 2,400’ of 42” RCP using an Akkerman Slurry Microtunnel Boring Machine (SL-44). There were 5 separate microtunnel drives, 3 of which encountered boulders requiring rescue shafts. Three drives crossed major highways and one drive crossed under the Pine Island Pond. The geologic report for the project stated the tunnel elevation was selected to avoid any boulders in the... Complete Project Profile

SUMMARY: The City of Raleigh, NC Public Utilities Department has constructed a major upgrade to its Crabtree Creek Interceptor system designed to alleviate hydraulic restrictions, accommodate future projected flows, and minimize SSOs by installing 41,000 lf of 54”, 60”, and 72” gravity sewer. A total of 5,000 lf broken into 14 separate drives by slurry microtunneling methods that went underneath... Complete Project Profile

SUMMARY: Phase 1 of the Crabtree Basin Wastewater improvements project consisted of 21,000 feet of 30" to 72" diameter gravity sewer pipe. Three segments were designed for trenchless construction by microtunneling. These included two road crossings and one crossing under existing 60" RCP pipeline connected to an active pump station. Bradshaw microtunneled all three crossings in rock and mixed face soil... Complete Project Profile

SUMMARY: This project was to install a 24" storm sewer pipe for the City of Portland, Maine. Bradshaw used an Akkerman SL-24 microtunnel boring machine to one pass pipe jack 24" Hobas sewer pipe from shafts constructed by the contractor. The challenge on this project turned out to be the ground conditions which included unexpected cobbles and boulders. These conditions stopped the microtunnel boring... Complete Project Profile

SUMMARY: This project involved jacking 468 feet of 87.5" steel casing under I-95 near Baltimore, MD. The soil conditions included sand, silt, & clay below the water table. Microtunneling was required by the owner due to the ground conditions and due to the sensitivity of I-95 (an 8 lane highway) to any disturbance. The casing was installed on line and grade without incident. Bradshaw also installed... Complete Project Profile

SUMMARY: After another subcontractor failed to complete a guided-bore, Bradshaw Construction was contracted for the installation of 280 linear feet of 43 inch steel casing and a 30 inch ductile iron sewer pipe for an interceptor. The casing was jacked behind a microtunnel boring machine through medium dense sands and sticky clay below the water table. Performing the microtunnel out of a shaft that was... Complete Project Profile

SUMMARY: Bradshaw Construction completed 4 drives of 63" Permalok steel casing by microtunneling in Landsdowne, MD. The 4 drives totaled 905 LF and were under CSX and Amtrak railroads, and US-1 and I-895 highways. The microtunnels were completed using a Herrenknecht 1200TC with a Soft Ground cutting head. The tunnels were originally designed to be 72" Hand Mined Liner Plate, but were changed to Permalok... Complete Project Profile

SUMMARY: This project involved the construction of six tunnels, totaling 1,600'. The tunnels passed under Maryland State and Howard County roads on three phases of Howard County's Little Patuxent Parallel Interceptor project. 60" of jacked steel casing was used to install 36 to 42" of fiberglass reinforced carrier pipe for a gravity sewer. Subsurface conditions ranged from alluvial deposits of gravel and... Complete Project Profile

SUMMARY: This project involved the construction of six tunnels, totaling 1,600'. The tunnels passed under Maryland State and Howard County roads on three phases of Howard County's Little Patuxent Parallel Interceptor project. 60" of jacked steel casing was used to install 36 to 42" of fiberglass reinforced carrier pipe for a gravity sewer. Subsurface conditions ranged from alluvial deposits of gravel and... Complete Project Profile

SUMMARY: This project involved the construction of two tunnels, totaling 450'. The tunnels passed under Maryland State and Howard County roads on three phases of Howard County's Little Patuxent Parallel Interceptor project. 59" of jacked steel casing was used to install 42" fiberglass reinforced carrier pipe for a gravity sewer. Subsurface conditions ranged from alluvial deposits of gravel and cobbles to... Complete Project Profile

SUMMARY: Bradshaw Construction completed 1,133 foot microtunnel of 96 inch steel casing in a single drive for the Metropolitan Sewer District, located just outside of Louisville, KY. The tunnel was a contractor bid alternate design from (6) separate tunnels to (1) cost-effective large, long tunnel. A 42 inch fiberglass sewer and 30 inch PVC force main were installed within the casing and grout... Complete Project Profile

SUMMARY: Bradshaw Construction installed 2,740' of 42" reinforced concrete pipe for a relief sanitary sewer by microtunneling through sand with cobbles and boulders below the groundwater table at an average depth of 20'. The microtunneling was accomplished in four drives, the longest of which was 810'. Six access shafts were constructed using steel ribs and liner plates (16' and 20' in diameter) and... Complete Project Profile

SUMMARY: Bradshaw Construction installed 5,200' of 72" reinforced concrete pipe for a sanitary sewer relief interceptor. 4,000' of pipe was installed by microtunneling through sand with cobbles and boulders and glacial till below the groundwater table at an average depth of 30'. The microtunneling was accomplished in six segments, the longest being 1,150' long using three intermediate jacking stations... Complete Project Profile

SUMMARY: The City of Cumming, GA constructed a new raw water intake in Lake Lanier. Bradshaw Construction was contracted to install the 66" steel casing pipe from the on shore pump station shaft to the intake structure at the bottom of the lake. The pump station shaft was constructed by the jet grout method. Bradshaw jacked the casing using a slurry microtunneling machine. The intake pipeline was designed... Complete Project Profile

SUMMARY: As part of a new chiller plant and distribution network, the University of Georgia had to install two 20" chilled water pipelines under the busy intersection of Baxter and Lumpkin Streets on campus. The design called for a single 59" steel casing to house both lines. Trenchless construction by microtunneling was specified to reduce impacts to the surface traffic and buried existing utilities and... Complete Project Profile

SUMMARY: This microtunnel project was part of the Design/Build Capital Improvements Program for the City of Tampa. For future city growth, Bradshaw microtunneled a 60" x 428' steel casing under the Hillsborough River for a new 36" DIP water main. Two shafts were constructed: a 23' ID x 45' deep launch shaft at Julian B. Lane River Park and a 10' OD x 40' deep drilled receiving shaft at the Straz... Complete Project Profile

SUMMARY: Bradshaw Construction was contracted by CH2MHill Constructors Inc. to design build 2,028 linear feet for 60 inch steel casing by microtunneling for a 42 inch ductile iron water main. Bradshaw worked along side Garney Company who installed the open cut portion of the project. The ground conditions consisted of soft ground below the water table. Most of the drives were completed under a heavily... Complete Project Profile

SUMMARY: This project consisted of a 477 linear feet of microtunnel for the 12th Street Force Main. We assisted in the construction of shafts. 60 inch Permalok steel casing was used for the microtunneling and 42" ductile iron carrier pipe that was installed within the casing and grouted in place. Ground conditions were soft and the tunnel was mined at minimum cover. Complete Project Profile

SUMMARY: Bradshaw Construction was contracted for this signature FDOT project to install the first one-pass microtunneling system using reinforced concrete pipe from 42 inch to 72 inch. The total linear footage for this gravity storm sewer project was approximately 2,600. The cover below the heavily traveled highways was less than one diameter in most instances to create the gravity flow storm system... Complete Project Profile

SUMMARY: Bradshaw Construction was part in a Tampa Design/Build project. This project consisted of 3 separate drives mined by microtunneling. The first drive consisted of 477 linear feet for 60 inch steel casing to accommodate a 48 inch force main. The second was 450 linear feet and the third at a length of 1,290 linear feet for 60 inch steel casing for a 42 inch force main. These drives were for... Complete Project Profile

SUMMARY: Bradshaw Construction was installed 229 linear feet of 51" steel casing by microtunneling for the City of St. Petersburg Water Department. A 36 inch water transmission main was installed inside the casing. During mining, Bradshaw managed to maintain line and grade through very loose sand to medium dense fine sand and slightly silty sand, all below the water table. Complete Project Profile

SUMMARY: Bradshaw was contracted to pipe jack and install a 44 inch Hobas pipe that was provided by Blevins Road Boring. Inc. The drives consisted of (2) twin runs to accommodate Progress Energy's underground transmission lines. The first twin run was 128 linear feet and the second was 207 linear feet, for a total of 607 linear feet for the project. The ground conditions consisted of soft ground... Complete Project Profile

SUMMARY: Bradshaw Construction contracted with Consolidated Edison (CES) to install 24" chilled water lines on an accelerated schedule in downtown Miami, Florida. The project consisted of open-cut, shafts, and installing 36" Permalok steel casing by microtunneling through limestone under city streets and the CSX Railroad. Four seperate tunnels were launched out of twin launch shafts. The launch shafts... Complete Project Profile

SUMMARY: Bradshaw Construction installed a total of 300 linear feet of 96 inch Permalok steel casing in two separate drives. The first drive was 75 linear feet under US Route 1 and the second was 225 linear feet under both Dixie Highway and Florida East Coast Railroad. A 66 inch prestressed concrete cylinder pipe was installed within the steel casing for both drives. The tunnels were constructed in... Complete Project Profile

SUMMARY: Bradshaw Construction installed 524 linear feet of 52.5 inch Permalok steel casing by microtunneling underneath the heavily traveled I-75 highway. We then installed a 36 inch ductile iron carrier pipe within the tunnel as a new water main. Bradshaw assisted the General Contractor with subcontractor supervision at no additional cost, helping to insure quality of the shaft and concrete work... Complete Project Profile

SUMMARY: Bradshaw Construction mined 2 separate microtunnel drives for the Florida Department of Transportation. One drive was 300 linear feet and the other run was 336 linear feet. A 48 inch and a 42 inch ductile iron pipe water main was installed within the 60 inch steel casing, respectively. The tunnels were below the water table and at a depth ranging from 10 to 30 feet deep. The soils consisted of... Complete Project Profile

SUMMARY: Bradshaw Construction completed two tunnels of 50" steel casing totaling 291' in Dover, DE. The steel casing was installed by microtunneling and used for 24" and 27" PVC sanitary sewer. There were two main challenges for the project. The greatest challenge was retrofitting a jacking shaft meant for auger-boring to suit the needs of slurry microtunneling. To do this, our crew formed and poured... Complete Project Profile

SUMMARY: Bradshaw construction completed a microtunneling installation of lined 60” steel casing with three (3) 6” HDPE airlines installed within the casing. The casing served as a water intake on the Tennessee River in Madison, Alabama. The MTBM was recovered underwater by the use of divers and was a true test in itself. The major challenge on the project was fighting the buoyant forces of the... Complete Project Profile

SUMMARY: Bradshaw Construction Corporation completed four soft ground tunnels under state roads and a CSX railroad by microtunneling as part of a 37,000 linear foot long sewer pipeline project. The tunnels ranged in diameter from 83 to 96 inches and 110 to 220 linear feet in length. The smaller tunnels were direct jack 78-inch Hobas pipe, and the larger railroad tunnels were 2-pass Permalok steel casing... Complete Project Profile

SUMMARY: Bradshaw Construction installed 120 linear feet of 60 inch welded steel casing by microtunnel. We overcame a significant change in ground conditions from the bid documents to mine through a full face of clay underneath the water table crossing below Central Illinois Railroad. In addition, the reception plan was modified due to utility conflicts which the General Contractor encountered during... Complete Project Profile

SUMMARY: Bradshaw Construction Corporation completed a microtunnel drive crossing under an interstate and state highway in Birmingham, Alabama. The project consisted of 1,174 feet of 59 inch jacked steel casing for a 36 inch ductile iron water main. Ground cover under the highways ranged from 10 to 100 feet while shafts were an average of 22 feet deep. Mining conditions began with a mixed face of... Complete Project Profile